(a) Field of the Invention
The present invention relates to contact structures of wirings and methods for manufacturing the same, and thin film transistor array panels including the same and methods for manufacturing the same.
(b) Description of the Related Art
Generally, wiring of semiconductor devices is to transmit signals without delay.
In order to prevent delay or distortion of signals, materials having low resistivity such as aluminum or aluminum alloy are generally used. However, since the physical and the chemical properties of the aluminum or aluminum alloy is not good, that is, the aluminum or aluminum alloy is easily oxidized and corroded, when connecting other conductive material in a contact portions, accordingly the characteristics of semiconductor devices are deteriorated. To improve a contact properties of the wire made of aluminum and aluminum alloy, a different material is then inserted. However, to form the wire of multi-layered structure, several etchant to pattern the wire of multi-layered structure are need, also many times of the photolithography steps are needed. Accordingly, the manufacturing method is complicated and production costs are increased.
On the other hand, a liquid crystal display (LCD) is one of the most popular flat panel displays (FPDS). The liquid crystal has two panels having electrodes for generating electric fields and a liquid crystal layer interposed therebetween. The transmittance of incident light is controlled by the intensity of the electric field applied to the liquid crystal layer.
In the most widely used liquid crystal display, the field-generating electrodes are provided at both the panels, and one of the panels has switching elements such as thin film transistors.
In order to prevent delay or distortion of signals, materials having low resistivity such as aluminum or aluminum alloy are also used in the liquid crystal display. However, in the case that ITO (indium tin oxide) as a transparent electrode is used as a pixel electrode or to reinforce pad portions, because of the poor contact properties between aluminum or aluminum alloy and indium tin oxide (ITO), a different material is then inserted therebetween and the aluminum or aluminum alloy must be removed in the pad portions to prevent the corrosion of aluminum and aluminum alloy. Accordingly, the manufacturing method is complicated.
On the other hand, a thin film transistor array panel is manufactured by a photolithography process. Since the photolithography process is expensive, the number of the photolithography steps needs to be minimized.